Modeling and analyzing of low pressure pipeline transients accompanying gas bubbles and cavitation

In order to predict pressure transients accompanying gas bubbles and cavitation inside low pressure pipeline in hydraulic system of aerospace,pressure transient mathematical model was given to describe the flow behavior in the pipeline.By using finite difference method,partial differential terms of spatial dimension in differential equations can be calculated.Mathematic models were presented for calculation of effective bulk modulus,friction,gas bubble and cavitation volume during the transients.The model of low pressure pipeline transients involves three parameters,i.e.initial gas bubble volume in oil,gas releasing time constant and resolving time constant.By making use of genetic algorithms(GA),parameter identification for the mathematical model of pressure transients was performed.Thus the model with parameters identified from GAwas obtained and simulated.Comparison between simulation results and experimental data shows that low pressure transient model is capable of predicting pressure pulsation accompanying gas bubbles and cavitation.